wordpress gallery plugin w/ download button

I’m doing a photography job for some friends, and they will be paying everything up front (I won’t be messing with prints), so I’m trying to find a professional way to host the photos and make them easy to download.
At this point I use my flickr pro account to host my images.

Is there a gallery plugin that is pretty easy to use that includes a “download original image” button? I have found loads of decent ones, but most don’t have an easy way do download the original image. Worst case is I include the link to the original image of flickr (either in the third party or official slideshow), but it would be a bit of a pain, even if I could figure out how to make the links automatically open in a new tab.

So any ideas?